With the rise of DevOps-based work positions, there has been an increase in the need for people who would be efficient in automated testing and development programs, like Selenium or Jenkins. These job positions usually offer great advantages, such as extended career opportunities and constantly rising salaries. It is no wonder that more and more people choose to aim at these job positions. However, to ace the job interview, these people need to prepare. And what better way to prepare than by studying Jenkins interview questions?
In this tutorial, we shall cover both the basic questions and the Jenkins interview questions and answers for experienced developers so that you might get a general understanding of what to expect in the job interview. We’ll figure out what is Jenkins, what it’s used for and why do people love it so much.
Table of Contents
- 1 Introduction
- 1.1 Question 1: What is Jenkins?
- 1.2 Question 2: Why should developers use Jenkins?
- 1.3 Question 3: What is ‘automated testing’?
- 1.4 Question 4: What is ‘continuous integration’?
- 1.5 Question 5: What do you need to start using Jenkins?
- 1.6 Question 6: What is the default security mechanism for user authentication?
- 1.7 Question 7: Name at least two of the most popular plugins for Jenkins.
- 1.8 Question 8: How do you backup your files?
- 1.9 Question 9: What is a ‘pipeline’?
- 1.10 Question 10: What are the three fundamental stages of a Jenkins pipeline?
- 2 Advanced Jenkins Interview Questions
- 2.1 Question 11: How does Hudson relate to Jenkins?
- 2.2 Question 12: Name two ways of how you could schedule a build.
- 2.3 Question 13: What are some of the most popular environment variables?
- 2.4 Question 14: How would you move a file from one server to the other?
- 2.5 Question 15: Should you use Jenkins together with Selenium?
- 2.6 Question 16: What are the best ways to make sure that your Jenkins database is secure?
- 2.7 Question 17: What is Ansible?
- 2.8 Question 18: What is an ‘agent’?
- 2.9 Question 19: What is a ‘Jenkinsfile’?
- 2.10 Question 20: What is the command to manually start Jenkins?
- 3 General Tips
- 4 Conclusions
Let us not waste any time and start with the most basic Jenkins interview questions that you might get asked during your job interview.
The questions being “basic” does not mean that they’re not important, though – if you flunk these, you’re probably not really going to make it to the more advanced ones, anyway. So, pay close attention and memorize – let’s take it from the top.
Question 1: What is Jenkins?
To put it very simply, Jenkins is an open-source, continuous integration-focused, Java-based automation server. Basically, if you’re a developer who is constantly creating new programs and various software, yet you’re not using Jenkins – you’re missing out big time. Jenkins allows developers to test their programs on the go, all while allowing to integrate upgrades and additional features through ought the process.
Question 2: Why should developers use Jenkins?
As one of the introductory interview questions on Jenkins, your potential employers might want to check what you deem to be as the most important features of Jenkins. Even though the answer seems to be very subjective, here are a few examples that you can consider:
- Easy to catch bugs early on;
- An automated testing process;
- Continuous integration.
Question 3: What is ‘automated testing’?
One of the main features (if not the main one!) that Jenkins is famous for is its automated testing function. It’s easy to read this online and then simply memorize that phrase just to blurt it out as an answer during one of the employer’s Jenkins interview questions. However, what if there’s this follow-up? As a concept, automated testing has become so popular that it is almost automatically assumed (no pun intended) that everyone should know what it is.
Automated testing is when a certain program (framework) tests your developed programs (web applications) without the need for human interference.
This is amazing because of several reasons – a lot of money and time is saved, testing happens much faster, there’s no room for any human-made error. This is one of those interview questions on Jenkins that you should really remember!
Question 4: What is ‘continuous integration’?
Another popular concept, especially if the job that you’re preparing for with these Jenkins interview questions is somehow related with the DevOps philosophy.
Continuous integration is a process when multiple tests are performed on a single project on a daily basis. This is done because there’s usually way more than one developer working on the project (program, app, etc.).
Question 5: What do you need to start using Jenkins?
There are two basic requirements to start using Jenkins – a viable source code repository and a build script that’s registered on that repository.
However, there are also two software requirements before you actually install Jenkins – Java Development Kit and Jakarta: Enterprise Edition.
Question 6: What is the default security mechanism for user authentication?
Although at first glance this might seem like one of the more advanced Jenkins interview questions, it’s actually pretty simple when you think about it.
You have a couple of options to choose from when it comes to identifying the user, but the default function in Jenkins is to store user data in the inner database.
Question 7: Name at least two of the most popular plugins for Jenkins.
Maven and Git are probably two of the most popular Jenkins plugins to date.
Question 8: How do you backup your files?
This is probably one of the few self-explanatory Jenkins interview questions that you might get.
The JENKINS-HOME directory contains all of your personal configurations. This means that the only thing that you need to do to keep your files safe and clean from any issues is to back up the directory.
Question 9: What is a ‘pipeline’?
The term “pipeline” is used to describe the process from a project earliest development stages all the way to its release to the public.
Question 10: What are the three fundamental stages of a Jenkins pipeline?
Build the project, test the project and then deploy the project.
Advanced Jenkins Interview Questions
Those were ten examples of what a typical beginning of your Jenkins job interview could look like. As you probably noticed, the questions are quite simple – they’re designed to check your general knowledge about Jenkins, automation, DevOps and so on.
Now that you can kind of know what to expect, we can transition to Jenkins interview questions and answers for experienced developers and programmers. These questions and answers are designed to check just how in-depth does your knowledge on the topic goes. Also, when it comes to these interview questions on Jenkins, they aren’t all necessarily super difficult – they’re simply much more technical.
Question 11: How does Hudson relate to Jenkins?
This is one of the more interesting Jenkins interview questions – it doesn’t only check the technical research that you’ve done on Jenkins, but also how deep have you dug when it comes to the program’s history.
A long time ago, Hudson was the official name (an earlier version) of what is now known as Jenkins.
Question 12: Name two ways of how you could schedule a build.
You could either issue commits to the management of the source code or, if you wished, you could manually request the builds.
Question 13: What are some of the most popular environment variables?
This type of Jenkins interview questions could be somewhat tricky to figure out, for employers might purposely try to make the questions much more difficult than they have to be.
Keeping in mind that question most likely relates to Jenkins build jobs, there are a lot of elemental variables that you could choose from. Here are a few of the more well-known ones:
Question 14: How would you move a file from one server to the other?
This is considered to be one of the advanced Jenkins interview questions mainly because there can be quite a few possible answers to it. However, if you want to keep it as simple as possible (which is quite advisable), there’s a very straightforward answer – simply copy the job directory and paste it in the other server.
Question 15: Should you use Jenkins together with Selenium?
Yes, it’s actually quite beneficial – this type of a combination runs immediate tests every single time that your program changes or alters in some way.
Question 16: What are the best ways to make sure that your Jenkins database is secure?
There are plenty of ways to ensure security is of the top level when it comes Jenkins, but some of the more notable ones include (but are not limited to) keeping global security on, running security checks, keeping your database protected on the physical level (not letting unauthorized personnel near it), etc.
Question 17: What is Ansible?
Ansible is a configuration management tool that has the ability to be used for provisioning and can be implemented into Jenkins.
Question 18: What is an ‘agent’?
An “agent” can be seen as a point of reference – it specifies a point in the pipeline in which Jenkins will be launched.
Question 19: What is a ‘Jenkinsfile’?
It is a text file containing all of the information about the project’s pipeline. It should always be implemented into the source control.
Question 20: What is the command to manually start Jenkins?
Up to this point, we have discussed what is Jenkins, talked about the basics and covered some of the main Jenkins interview questions and answers for experienced users. Now that you can kind of imagine what to expect from the job interview, I’d like to discuss some of the more general things that you could do before, during and after the interview.
Before the Interview
So – you’ve scheduled your interview, it’s a week away, and you’re ready to start preparing. There are plenty of different things that you could do to maximize the chance of you actually landing that job.
First of all, develop a schedule for studying. And this doesn’t mean that you have to study for 16 hours per day – a lot of people think that if they do nothing else than study and repeat for the entire time up until the interview, that will make them more likely to succeed. Actually, the opposite is true – there is such a thing as “overstudying”, and if you get completely burned out, your performance will suffer.
Instead, make sure that you have the time to both study and rest. I know you’ve probably heard it a million times before, but sleep is very important in these types of scenarios. Also, make sure that you make time for personal activities – again, a burnout won’t do you any good!
Another tip that I can give you revolves around studying itself. Naturally, there are many different ways that you could study. However, a great method of choice seems to be one that involves sticky notes.
What you could do is take a tutorial just like this one and write the questions and answers down on both sides of the note – that’s a great way of memorizing information. Also, you can simply paste the stickers all around, so that whatever you’re doing, you always see them and passively revise the subject material.
During the Interview
You’ve done all of the reading and studying that you could, and now the time has come to show what you’ve learned. The very first thing that you should aim to do is leave a lasting, good first impression. Smile, be polite and try to loosen up – your potential employers will most likely appreciate it.
Now, all that you need to do during the interview is to demonstrate that you’ve put the effort into studying those Jenkins interview questions and that you have a reliable personality. The question part is easy – your interviewers ask, and you answer. Try not to give one blank statement answers – elaborate with two or three sentences to the best of your ability. This will show that you truly are knowledgeable on the topic.
As for your character – be humble, don’t try to artificially impress your potential employers and don’t come off as grumpy or ill-mannered. Simple as that!
After the Interview
There’s honestly not that much that you can do after the interview. Naturally, you probably shouldn’t call your interviewers every single day twenty times per day asking if you got the job – not the best idea!
Try to relax – they’ll get back to you! One thing that you can do at this point is to reflect on the experience that this job interview gave you, and how you could use it in future interviews.
In this tutorial, we have talked about the basics that you should know when thinking about your Jenkins job interview, covered some of the more popular Jenkins interview questions for experienced developers and discussed what is Jenkins overall. I’ve also provided you with some general tips that you could apply before, during and after your job interview.
As the philosophy of DevOps is becoming more popular and widespread, the need for qualified developers is rising. Since DevOps is a wide term, such developers are required to possess an equally wide range of abilities – knowing how to use Jenkins is one of them. Since the concept of automation is taking the programming and development world by storm, tools like Jenkins and Selenium are becoming essential if you want to keep up with the market. This, in turn, creates great job opportunities.
Study hard, remember to rest and just be yourself – you’ll ace that job interview!